An absolutely fascinating episode. The information from the historic geologists and also the non geologist specialists in their related fields (Ron Reppin- gold) and Carl Carlson (blue agates) was wonderful. I will rewatch this episode to get everything possible out of it.
WOW, Nick I was with you from your first backyard broadcast, but these days, I have to keep my focus on work and also, I have to catch everything in replay. Further, I have also re-watched session two or three times. This allows for multiple trips to the provided documents to read up. Back to the WOW, I am amazed at the journey your questioning took on this one took and it did spawn some interesting questions--some from your topic experts in your live on live crowd and the average fans like me. What amazes me is how you catalog varies datum points from a range of sources and tie it all together. Part of the charm is that you present the data points in a way that your fans can put them on the mental shelf. I love it in the question time, you complain that some question is off topic... all that signals that you are just seeing your past successes where we appreciated a Zentner past point and want to "use it." Nick, I like waking up early in the morning and doing a full session to get the mental juices flowing. It gets me ready to plug through my technical problems. Thanks again.
These are great videos. I am no geologist, by any stretch, but I bike everywhere and have been exploring the PNW, and this is a great explanation for what I'm looking at (and where I should go next). It's also a great pronunciation key for all these places. :)
I just want to say thank you to Nick for opening my eyes to these mafic enclaves. When I learned about them here a few weeks ago, I thought I'd seen them in the archaean granites where I grew up. I went home for Christmas, and due to the unseasonably warm weather, I was able to get out and investigate, and found _absolute textbook_ dykes that end up disseminating into enclaves! It's quite remarkable how many similarities there are between these vastly ancient granites and basalts and their more contemporary counterparts on the West coast. There is bimodal volcanism here, there are vesicular agates, there are extensional areas loaded with mafic dykes.... Thank you again, Mr. Zinger, you truly are a top-notch teacher!
Nick, I, for one, appreciate giving the full background of the Cascade basement. The Arc wasn't a solitary story, and you are giving us the foundation. The Cascades are so full of interesting features. I was born & raised here. I always knew the Cascades were volcanic. What I didn't know until I found you was the exciting rock that exists there. The Cascades are messy and choppy and so worth our time. Thank you for teaching us, for showing us, for demonstrating what an awesome place Washington State is.
Another great instructive and challenging video. I want to especially thank you and Dr. Tepper for posting the excellent "Bimodal Vulcanism" note. This provides an answer to a question I've had since visiting Newberry Volcanic Monument this summer as part of a wide ranging visit to the Cascades. Newberry just didn't seem to fit, and the question had begun to bug me as I learned a little more about bimodal vs. BADR vulcanism. This is science, so I know this is AN answer, and not necessarily THE answer to my question, but it seems like a pretty good one, and I'll go with it until shown otherwise. Again, many thanks.
Loved this episode, Nick! (and all the others 😉) I especially liked how you added in the older videos about the blue agates and the wired gold. It gives us a broader insight in the origins thereof. Thank you!
Thanks Nick! This was an exciting episode. All is helping me in putting the geologic pieces together. Thankful for the samples and slides and map locations. Very helpful!
1:18:40 Beautiful map of the feeder dikes by Otis. Remember though that the PNW has rotated by 50° since the Eocene. So the Teanaway extension was perpendicular to a perfectly north-south active margin in the Eocene. The phreatomagmatism really interests me. I can’t think of a modern analog for this-a tropical, low-elevation maar-diatreme/fissure complex with bimodal rhyolite caldera volcanism. There are plenty of maar+caldera fields in the Pleistocene of Oregon, there are the Hopi Buttes volcanoes from the Mio-Pliocene in Arizona, the Pleistocene Potrillo Volcanic Field in New Mexico, and the Pinacate volcanic field in Mexico, but those are all mostly too northern latitude-they were wetter and drowned with pluvial lakes and wetlands when they were erupted, but not exactly tropical by any means. Also, these fields are mostly just basaltic monogenetic fields-not bimodal volcanism with rhyolitic calderas. There are tropical maar fields in Indonesia (Lamongan Volcanic Field on Java) and the Philippines (East Luzon), and these are associated with active arcs and even some caldera volcanoes, but they aren’t bimodal as far as I am aware-not slab break off magmatism at this point. The Nevsehir-Acigöl Volcanic Complex in Turkey fits the styles of volcanism, but again-not tropical. Perhaps some volcanic areas of Mexico and Central America are somewhat close-I am thinking of Aljojuca Maar and associated maars and silicic volcanism in the Trans-Mexican Volcanic belt-pretty tropical. But the quantity of basalt erupted is not nearly as much as the Teanaway it seems. The Roman/Central Magmatic Province of Italy features tons of maar-diatreme volcanoes (Colli Albani, etc) and silicic caldera volcanism (Campi Flegrei and the Campanian Ignimbrite suoervolcanic eruption), but again, the basaltic fissure volcanism and lava production is not near the level of the Teanaway-and not tropical. The particular combination of tectonic setting, style of volcanism, and climate/biome that the Teanaway formation represents is very unique. Also regarding what that Carl guy said about “rubies”: I always thought that ruby was only associated with high grade granulated-facies metamorphism, so I looked this up thinking he was mistaken, but I’ve come to learn that there are actually occurrences of rubies associated with continental alkaline basaltic volcanism. This is a relatively new finding-the dogma has always been ruby=high grade metamorphism and ancient, denuded orogenic belts. 1:45:00 Ok, so this changes things. So do we even have actual bimodal volcanism ala Tepper? Or we have both the Eocene bimodal volcanism plus younger cascades rhyolites coming up through the Teanaway? What proportion of the rhyolites are coeval with the basalts versus the younger set?
This was a good episode for the day after Christmas: not many new ideas to digest. Next year I need to take a trip through the Teanaway concentrating on the rocks underfoot instead of the much more ostentatious rocks in the vicinity.
Hey Nick have you looked into Walker valley much? We rockhound there, there rhyolite with basalt in that locale as well. It is in the northern section you were searching for them near Mt Vernon, with very similar agates and geodes to the teanaway and liberty areas. I believe localities around it have been dated 39-52ma
Personally I think the rhyolite came after the basalt. I've got a spot I mine Calcite nodules out of rhyolite and the rhyolite comes out in veins in the basalt where the basalt was cracked and the rhyolite came up.
Looking forward getting back to Basil Tikoff take on the whole thing with Idaho, Cascades and everything. Sure he will have his own take on all things said until now.
If the dikes are intruding through cracks caused by uplift prior to 49Ma would the same directional trending cracks apply to the younger 26Ma intrusive dikes? This in response to one of the questions in the QA at the end…
An absolutely fascinating episode. The information from the historic geologists and also the non geologist specialists in their related fields (Ron Reppin- gold) and Carl Carlson (blue agates) was wonderful. I will rewatch this episode to get everything possible out of it.
WOW, Nick I was with you from your first backyard broadcast, but these days, I have to keep my focus on work and also, I have to catch everything in replay. Further, I have also re-watched session two or three times. This allows for multiple trips to the provided documents to read up. Back to the WOW, I am amazed at the journey your questioning took on this one took and it did spawn some interesting questions--some from your topic experts in your live on live crowd and the average fans like me.
What amazes me is how you catalog varies datum points from a range of sources and tie it all together. Part of the charm is that you present the data points in a way that your fans can put them on the mental shelf. I love it in the question time, you complain that some question is off topic... all that signals that you are just seeing your past successes where we appreciated a Zentner past point and want to "use it." Nick, I like waking up early in the morning and doing a full session to get the mental juices flowing. It gets me ready to plug through my technical problems. Thanks again.
These are great videos. I am no geologist, by any stretch, but I bike everywhere and have been exploring the PNW, and this is a great explanation for what I'm looking at (and where I should go next). It's also a great pronunciation key for all these places. :)
I just want to say thank you to Nick for opening my eyes to these mafic enclaves. When I learned about them here a few weeks ago, I thought I'd seen them in the archaean granites where I grew up. I went home for Christmas, and due to the unseasonably warm weather, I was able to get out and investigate, and found _absolute textbook_ dykes that end up disseminating into enclaves! It's quite remarkable how many similarities there are between these vastly ancient granites and basalts and their more contemporary counterparts on the West coast. There is bimodal volcanism here, there are vesicular agates, there are extensional areas loaded with mafic dykes.... Thank you again, Mr. Zinger, you truly are a top-notch teacher!
👍 Caught the replay, greatly enjoyed.
No hurry to get to the modern Cascade arc Nick - this has been a blast! Looking forward to the next one.
Watching in replay most of this series. Enjoying.
Wonderful fulling episode thanks to all who contributed especially Proffessor Zenter
Such a GREAT episode bringing many prior and new concepts to satisfying comprehension!!!
Love these Zentner flics from LeChee, Arizona
Nick, I, for one, appreciate giving the full background of the Cascade basement. The Arc wasn't a solitary story, and you are giving us the foundation. The Cascades are so full of interesting features. I was born & raised here. I always knew the Cascades were volcanic. What I didn't know until I found you was the exciting rock that exists there. The Cascades are messy and choppy and so worth our time. Thank you for teaching us, for showing us, for demonstrating what an awesome place Washington State is.
Aloha from Bali! Thank you for continuing this awesome series on Cascade volcanism.
Thanks for all the hard work on these videos!
Love that you’re still doing down-town lectures…that’s where I found you online a while back.
Another great instructive and challenging video. I want to especially thank you and Dr. Tepper for posting the excellent "Bimodal Vulcanism" note. This provides an answer to a question I've had since visiting Newberry Volcanic Monument this summer as part of a wide ranging visit to the Cascades. Newberry just didn't seem to fit, and the question had begun to bug me as I learned a little more about bimodal vs. BADR vulcanism. This is science, so I know this is AN answer, and not necessarily THE answer to my question, but it seems like a pretty good one, and I'll go with it until shown otherwise. Again, many thanks.
Loved this episode, Nick! (and all the others 😉)
I especially liked how you added in the older videos about the blue agates and the wired gold. It gives us a broader insight in the origins thereof. Thank you!
Thanks Nick! This was an exciting episode. All is helping me in putting the geologic pieces together. Thankful for the samples and slides and map locations. Very helpful!
Awesome, thanks, Nick, Mike,,,,,YOU MADE my day! Must watch and enjoy the moment video!!😘💞✨💗
I am getting caught up. Hope to join you live soon.
I am trying to catch up. Great work.
thank you
That was excellent. Ty. Wish you could date one of those samples. Just beautiful. Have a great Christmas weekend.
1:18:40 Beautiful map of the feeder dikes by Otis. Remember though that the PNW has rotated by 50° since the Eocene. So the Teanaway extension was perpendicular to a perfectly north-south active margin in the Eocene.
The phreatomagmatism really interests me. I can’t think of a modern analog for this-a tropical, low-elevation maar-diatreme/fissure complex with bimodal rhyolite caldera volcanism. There are plenty of maar+caldera fields in the Pleistocene of Oregon, there are the Hopi Buttes volcanoes from the Mio-Pliocene in Arizona, the Pleistocene Potrillo Volcanic Field in New Mexico, and the Pinacate volcanic field in Mexico, but those are all mostly too northern latitude-they were wetter and drowned with pluvial lakes and wetlands when they were erupted, but not exactly tropical by any means. Also, these fields are mostly just basaltic monogenetic fields-not bimodal volcanism with rhyolitic calderas. There are tropical maar fields in Indonesia (Lamongan Volcanic Field on Java) and the Philippines (East Luzon), and these are associated with active arcs and even some caldera volcanoes, but they aren’t bimodal as far as I am aware-not slab break off magmatism at this point. The Nevsehir-Acigöl Volcanic Complex in Turkey fits the styles of volcanism, but again-not tropical. Perhaps some volcanic areas of Mexico and Central America are somewhat close-I am thinking of Aljojuca Maar and associated maars and silicic volcanism in the Trans-Mexican Volcanic belt-pretty tropical. But the quantity of basalt erupted is not nearly as much as the Teanaway it seems. The Roman/Central Magmatic Province of Italy features tons of maar-diatreme volcanoes (Colli Albani, etc) and silicic caldera volcanism (Campi Flegrei and the Campanian Ignimbrite suoervolcanic eruption), but again, the basaltic fissure volcanism and lava production is not near the level of the Teanaway-and not tropical.
The particular combination of tectonic setting, style of volcanism, and climate/biome that the Teanaway formation represents is very unique.
Also regarding what that Carl guy said about “rubies”: I always thought that ruby was only associated with high grade granulated-facies metamorphism, so I looked this up thinking he was mistaken, but I’ve come to learn that there are actually occurrences of rubies associated with continental alkaline basaltic volcanism. This is a relatively new finding-the dogma has always been ruby=high grade metamorphism and ancient, denuded orogenic belts.
1:45:00 Ok, so this changes things. So do we even have actual bimodal volcanism ala Tepper? Or we have both the Eocene bimodal volcanism plus younger cascades rhyolites coming up through the Teanaway? What proportion of the rhyolites are coeval with the basalts versus the younger set?
Those old maps are indeed georgeous.
Merry Christmas!!
This was a good episode for the day after Christmas: not many new ideas to digest. Next year I need to take a trip through the Teanaway concentrating on the rocks underfoot instead of the much more ostentatious rocks in the vicinity.
Missed the first 25 minutes live. (Dog ate my homework? lol) Watched the Index Granite vid from "Nick on the Rocks" a bit ago. Good stuff. Thx!
Hey Nick have you looked into Walker valley much? We rockhound there, there rhyolite with basalt in that locale as well. It is in the northern section you were searching for them near Mt Vernon, with very similar agates and geodes to the teanaway and liberty areas. I believe localities around it have been dated 39-52ma
Thank goodness for the coinpurse I would have never seen this
@nick Statia Gordon is our uplift expert, right? maybe at least as it pertains to metamorphic petrology, geochem, depth of burial, right?
Is the break off why there are little rhyolite bits on all the trails in the Col Rvr Gorge ?
No ads here (YT premium)
So has the broken off section of the plate been fueling the Cascade volcanics and also helping to create the Cascades
remember when youtube was supposed to a place for free content - having ads every 5 minutes or so
So... are there any spidergraphs of the young Rhyolites? Are they fresh arc, or could they be breakoff stuff pushed ahead of arc magmas?
Personally I think the rhyolite came after the basalt. I've got a spot I mine Calcite nodules out of rhyolite and the rhyolite comes out in veins in the basalt where the basalt was cracked and the rhyolite came up.
Looking forward getting back to Basil Tikoff take on the whole thing with Idaho, Cascades and everything. Sure he will have his own take on all things said until now.
If the dikes are intruding through cracks caused by uplift prior to 49Ma would the same directional trending cracks apply to the younger 26Ma intrusive dikes? This in response to one of the questions in the QA at the end…
I thought the dikes had rotated 45 degrees, -or was that a different set of dikes??
Lots of rhyolite on slid ridge on lake chelan.
Depends on WHO broke the plate
What happened to the chat? Am I missing a setting?
The live chat goes away after the live stream, Nick has no control over that, it is a You Tube thing.
@@charlesward8196 It does come back, but the timing is all up to RUclips.
Lava soap rules! It’s pumice powered. 🌋 🧼